Police investigating the Manchester bombing agreed to a secret request from the Royal Ulster Constabulary not to arrest and interview a prime suspect, a court has heard.

A file that was being prepared for the Crown Prosecution Service about the 1996 explosion was not forwarded for another 16 months as a result, according to a former head of Greater Manchester Police Special Branch.

The ex-officer said police making inquiries into the lorry bomb that blew apart the city centre were given a "cover story" to account for the fact that no arrest had been made.

No copies were ever taken of that agreement because of its sensitive nature

Witness

The former Special Branch chief, who retired in July last year, was giving evidence at the trial of Detective Chief Inspector Gordon Mutch, who denies leaking details of the investigation, including the identity of a prime suspect to a Manchester Evening News crime reporter in 1999.

Mr Mutch, 51, pleads not guilty to misconduct in a public office.

The witness, giving evidence from behind a curtain and through a voice distortion machine, was named at Manchester Crown Court only as Mr Bernard.

He said that at a meeting in Manchester in March 1997 he and former Assistant Chief Constable Colin Phillips were asked by a senior RUC officer not to arrest and interview a suspect.

'Lives at risk'

As a result, a file they were preparing for the CPS, which could have advised that the arrest should go ahead, was not sent.

An agreement was drawn up and signed by Mr Phillips and later by Greater Manchester Chief Constable David Wilmot.

Mr Bernard said the only copy was locked in his safe.

"No copies were ever taken of that agreement because of its sensitive nature," said the witness.

"Without over-dramatising, lives would have been at risk if the IRA had known what was in that agreement."